Birch Bay Siding Board & Batten Siding Built for Custer's Coastal Climate
Custer sits in the quieter, more rural stretch of Whatcom County just inland from the Birch Bay shoreline, close enough to Drayton Harbor and the Salish Sea that the same salt-laden air, wind-driven rain, and shaded, moss-friendly conditions that define the Birch Bay coastline reach the farmhouses, acreages, and newer builds here too. Board and batten siding has become a popular choice in this area because of its clean vertical lines and strong, farmhouse-style curb appeal, but the look only holds up if the material and installation underneath it are built for this specific climate. This page covers what board and batten siding needs to survive and look right in Custer, what a correct installation actually involves, and why we install it exclusively in James Hardie fiber cement rather than the vinyl, LP SmartSide, or wood alternatives also sold under the "board and batten" name.
Why Custer's Climate Is Harder on Vertical Siding Than It Looks
Board and batten siding relies on vertical panels with raised battens covering the seams — a design that channels water downward rather than sideways, which is generally a good thing in a wet climate. But that same vertical run creates long, continuous joints and a lot of exposed batten edge, and in Custer's conditions those details are exactly where problems start.
Salt Air and Corrosion
Custer isn't waterfront, but it's close enough to Birch Bay and the broader Salish Sea coastline that airborne salt still reaches siding, fasteners, and trim, especially on homes with west or southwest exposure. Over years, salt-laden moisture accelerates corrosion on lower-grade fasteners and metal trim, and it degrades paint films faster than inland exposure would. Board and batten's many exposed batten strips mean more total fastener points and more painted edge grain exposed to that air than a horizontal lap profile has.
Driving Rain
Whatcom County's weather regularly comes in sideways off the water, and Custer gets its share of wind-driven rain events, not just steady vertical drizzle. Wind-driven rain finds its way into gaps and gets forced upward and sideways behind trim and battens, not just downward with gravity. A board and batten system needs a real drainage plane and correctly lapped water-resistive barrier behind it, or that driving rain will eventually find the sheathing.
Moss Season
Whatcom County's moss season runs long — realistically most of the fall through spring — and it's worse on siding faces that stay shaded or don't dry out quickly, which describes a lot of tree-lined and north-facing property in and around Custer. Moss holds moisture against the surface for extended periods. On a product that isn't dimensionally stable or properly sealed, that constant damp contact is where swelling, softening, and paint failure start.
What a Correct Board & Batten Installation Actually Involves
The style is simple to describe, but doing it correctly in a climate like Custer's takes more than nailing up boards and battens. The details that matter are mostly hidden once the job is finished, which is exactly why they get skipped by crews trying to move fast.
Drainage Plane and Rainscreen Gap
Vertical siding should be installed over a code-compliant water-resistive barrier with a drainage gap behind the panels, not nailed flat against the sheathing. That gap lets any moisture that does get past the surface drain and dry instead of sitting against the wall assembly — critical in a driving-rain, high-humidity area like this one.
Fastening Pattern and Panel Layout
Panels and battens need to be fastened per the manufacturer's engineering specs, with correct edge distances, fastener spacing, and blocking at horizontal joints. Loose or under-fastened panels flex in wind, which opens joints over time and lets water in exactly where it shouldn't be.
Flashing, Trim, and Sealant Strategy
Every horizontal break — window and door heads, transitions to roof lines, water tables at the base of the wall — needs proper flashing that sheds water out and away, not caulk alone standing in for it. Caulk has a service life and isn't a substitute for physical flashing; it's a supplement to it. This matters more on board and batten than on lap siding because vertical panels have more transitions to seal correctly at the top and bottom.
Field Cuts and End Grain
Every field cut, notch, and panel end exposes raw material that needs to be sealed before installation, not after the fact. This is one of the most commonly skipped steps on rushed jobs, and it's one of the fastest ways for moisture to enter a board and batten wall from the inside out.
Why We Install James Hardie for Board & Batten — Not Vinyl, LP, or Wood
"Board and batten" isn't a brand — it's a style, and it's sold in several materials with very different real-world behavior. We install James Hardie fiber cement exclusively, and in a climate like Custer's, the reasoning is straightforward.
Vinyl board and batten is lightweight and inexpensive, but it expands and contracts significantly with temperature swings, which stresses the long, thin battens more than it stresses shorter horizontal panels. It also can't be painted a dark color without risking warping in full sun, which limits the farmhouse color palette that draws people to this style in the first place.
LP SmartSide and other engineered wood products use a wood-strand core with a resin-treated surface. It performs reasonably well when installation is flawless, but any breach in that surface treatment — a bad cut edge, a missed sealant joint, sustained moss contact — gives moisture a path into a wood-based core, and wood-based cores swell and deteriorate once they take on water. Given how long moss season runs here, that's a real long-term risk we're not willing to install and stand behind.
Solid or primed wood board and batten looks great initially but demands the most ongoing maintenance of any option — regular repainting, caulk inspection, and vigilance against rot — maintenance that's harder to keep up with in a climate that stays damp and shaded for large parts of the year.
James Hardie fiber cement is cement-based, not wood-based, so it doesn't swell, rot, or feed moss growth the way organic materials can. It's non-combustible, holds paint and factory-applied ColorPlus finishes far longer than primed wood, and Hardie's HZ5 product line is specifically engineered for climates like ours — freeze-thaw cycling, sustained moisture, and coastal exposure. That combination is why it's the only board and batten product we put on Custer homes.
Comparing Board & Batten Materials for Custer's Climate
| Factor | James Hardie Fiber Cement | Vinyl | LP SmartSide / Engineered Wood | Solid Wood |
|---|---|---|---|---|
| Moisture & rot resistance | Cement-based, does not rot or swell | Doesn't rot, but seams can trap moisture | Vulnerable if surface treatment is breached | Vulnerable without diligent upkeep |
| Salt air / coastal durability | Engineered HZ5 line for coastal exposure | Holds up but can chalk and fade | Moderate; depends on finish integrity | Weakest; finish degrades fastest |
| Moss & shade tolerance | Doesn't feed moss growth; dries without swelling | Doesn't feed moss but traps damp behind panels | Sustained moss contact risks the wood core | High risk with extended shade/moisture |
| Color/finish longevity | Factory ColorPlus finish, long warranty | Limited to lighter colors; can warp in dark tones | Field or factory finish; needs maintenance | Repainting every few years |
| Fire resistance | Non-combustible | Combustible | Combustible | Combustible |
Our Process, Start to Finish
We keep the process the same whether it's one wall or a full re-side, because skipping steps is exactly how a job stops performing five years earlier than it should.
- On-site assessment: We walk the property, check existing siding and sheathing condition, and note shaded, moss-prone, and high wind-exposure areas specific to your lot.
- Detailed estimate: A written scope covering material, drainage plane approach, trim details, and timeline — no vague allowances.
- Prep and water-resistive barrier: Removal of failing siding, sheathing repair where needed, and installation of a correctly lapped weather barrier with rainscreen gap.
- Panel and batten installation: Hardie panels and battens installed to manufacturer fastening specs, with sealed field cuts and properly flashed transitions.
- Trim, caulk, and finish check: Final detailing at windows, corners, and the water table, followed by a walkthrough before we call the job done.
Living With Board & Batten Siding in a Moss-Prone Climate
Even a correctly installed board and batten system benefits from a little seasonal attention in a climate like Custer's, especially on shaded or north-facing walls where moss tends to establish first.
- Rinse siding and battens once or twice a year to clear moss spores, pollen, and organic buildup before it takes hold
- Trim back tree limbs and shrubs that keep any wall face in constant shade and damp
- Check caulk joints at windows, doors, and the water table annually and re-seal if it's cracked or pulling away
- Keep gutters and downspouts clear so roof runoff isn't dumping extra water onto siding below
- Watch for any soft spots, discoloration, or persistent staining and have them looked at before they spread
Because Hardie fiber cement doesn't rot or swell, this maintenance is about keeping the finish and caulk lines in good shape, not fighting off material failure.
Why Hiring a Crew That Already Works in Custer Matters
Board and batten siding is unforgiving of installation shortcuts, and a crew that hasn't worked this specific stretch of Whatcom County doesn't automatically know which walls on a given lot see the worst wind-driven rain, which sides stay shaded long enough to grow moss first, or how much salt exposure a property this close to Birch Bay's coastline actually gets. That local pattern recognition shapes real decisions — where extra flashing attention matters most, which elevations to prioritize, how a home's specific site conditions should factor into the plan — decisions a crew coming in cold has to guess at instead of already knowing.
It also matters for accountability. A local, James Hardie-focused crew that stands behind its work in this community has every reason to install it correctly the first time, because callbacks and long-term performance in a climate this demanding are the actual measure of the work — not just how the wall looks on the day it's finished.
If you're planning a board and batten project in Custer, we're glad to walk your property, talk through what your home's specific exposure needs, and put together a free, no-pressure estimate using the form below.